Control device for parking meters



June 22, 1954 J. A. T. ELLISON 2,681,960

CONTROL DEVICE FOR PARKING METERS Filed Nov. 29, 1949 2 Sheets-Sheet 1 June 22, 1954 J. A. T. ELLISON 2,681,

CONTROL DEVICE FOR PARKING METERS Filed Nov. 29, 1949 2 Sheets-Sheet 2 llll/I/ /III INVENTOR.

JOHN A. 77 LISO/V.

'driven from the zone.

Patented June 22, 1954 UNITED STATES PATENT OFFICE CONTROL DEVICE FOR PARKING METERS John A. T. Ellison, Seattle, Wash. Application November 29, 1949, Serial No. 130,046

2 Claims. 1

' This invention relates to a parking meter-control for automatically nullifying any residue of time remaining on themeter when an automobile parked in a parking zone related thereto is A principal part of said control system is a normally closed switch unit activated and opened by the magnetic attraction of an adjacent parked automobile.

An object of my invention is to provide a control system that can be utilized with a variety 'of different parking meters without necessitating fmaterial alterations of the latter.

A further object of my invention is to provide a control system including electrically actuated means requiring only a minute amount of electrical energy to nullify the time reading of a 1 parking meter and which causes the electric circuit to be automatically deenergized when the nullifying action is accomplished.

Another object of my invention is to furnish 'a parking meter control system which is not readily subject to tampering by pranksters, and

i which will also preclude the inadvertent closing of the circuit of the control system in a situation where, say, a magnet-effecting metal body such as a tool box is set down adjacent the zone in which a car has been parked.

My invention also has as an object the providing of a magnetic switch unit for use in my parking meter control system which unit is dependable in operation, is not subject to oxidation, does not arc at the poles, is effectively dampened, is of simple and economic construction, and can be easily and expeditiously installed. I With the above and other still more particula'r objects and advantages in View and which,

-with the foregoing,'will appear and be understood in the course of the following description and claims, the invention consists in the novel construction and in the adaptation and combi-' nation of parts' hereinafter described and "claimed. 11? In the drawings:

Figure l is a schematic plan view of my control system showing an automobile in the related parking zone and with the meter dial covered by a 'flag nullifier.

modification of my magnetic switch unit..

Fig. '5 is a horizontal sectional View showing tzl still another modification of the magnetic switch, the switch being in this instance illustrated in a closed position.

Fig. 6 is a horizontal sectional view of yet another modification of the magnetic switch unit, portrayed in open position.

Fig. '7 is a vertical sectional view on line 11 of Fig. 6. I

Figs. 8 and 9 illustrate a further modification with the former view being a horizontal section and the latter view a vertical section of Fig. 8.

Fig. 10 is a schematic plan view illustrating close-coupled switches in series for a purpose hereinafter to be described; and v Fig. 11 is a fragmentary schematic plan view which is to be read in conjunction with Fig. 1 to indicate the two positions of the nullifying flag.

My control system is particularly adapted to be used in conjunction with a conventional or suitable coin operated type of parking meter such, for example, as one in which a clock-driven hand is moved along the face of a dial marked from 0 to 60. The insertion of a coin moves the hand to the end of the dial and the clock then moves the hand toward the zero end with the passage of time, the position of the hand indicating on the dial the minutes of legal parking time remaining. The principal function of my control system is to provide a mechanism which will automatically block off the dial or otherwise effectuate a nullifying function upon the dial when a parked car is driven from the related parking zone with time still remaining upon the dial, thus to preclude such remaining time being used by another car moving into the parking zone.

As the nullifying agent, I have elected to show a flag 24 whose staff 26 is pivotally mounted at 25 in the head 23 of the meter. Also housed in the head 23 are a knife-switch 3i! and a solenoid 21' having a core 28. An arm 29 is provided as an extension of the core 28 and has its other end pivotally connected to the base of the staii 26. The free end of the knife or blade of the switch is operatively interconnected with the base of the staff 26 by means of a link It. In Fig. 1 the dial 22 is shown exposed with the switch 30 closed and the solenoid 27 in an inactivated state. It can be readily seen that if the solenoid 21 is energized so that the core 28 is drawn into the solenoid coils, the arm 29 will be forced away from the solenoid causing the flag 24 to move counter-clockwise into a nullifying position over the dial 22 and also causing the link [3 to open the switch 30, all as illlustrated in Fig. 11. Yieldingly opposing the counter-clockwise movement of the flag 24 is a tension spring 32 connected at one end to the stafi 26 and having its other end anchored to the meter head 753. Hence when the flag 24 is moved from the Fig. l to the Fig. 11 position the spring 32 is tensioned and, upon inaction of the solenoid 21, would act to return the flag back to the Fig. 1 position were it not for a catch 33 which is caused to normally lodge itself as a stop arm behind the fiag staff 26 and which is so associated with the coin chute as to be momentarily depressed into a staff-releasing position by passage of an inserted coin along the coin chute. This perforce allows the spring 32 to assert itself and swing the flag 24 clear of the dial 22 into the Fig. lposition. The staff when it occupies its spring-retracted position, may itself act to hold the latch depressed by overlying the same.

In series with the solenoid =2! and switch 30 in an electric circuit 36 are batteries 35, desirably dry-cell, preferably housed in the meter base 3 2, and also connected in series in this circuit are magnetic switches 3i and 3B of the type hereinafter set forth. These switches are embedded adjacent the curb 20 of a parking zone shown in Fig. 1 as being occupied by a car 39. The circuit 36 is grounded at 40 and 3|. At this point clarity in an understanding of the invention will perhaps be advanced by stating that at least one of the switches 3'! and 38 will be opened by the attraction of the car 39 when it is parked in the related zone and thus the circuit 36 will always be open when a car is parked. After the car enters the parking .zone but before a coin :is inserted the flag will be in the Fig. 11 position nullifying the dial 22. The interjection of a coin into the meter depresses the catch 33 to free the staff 26 so that the tensicned spring 32 is enabled to swing the flag 24 to the Fig. 1 position wherein the meter is exposed and the switch 30 is simultaneously closed. When the car is driven from the zone the magnetic switches 31 and 38 take normal positions reflecting the influence of the earths magnetic pull, positions which, more especially, close the switches to complete a circuit from the batteries 35 through the solenoid .21 inasmuch as the switch 30 is also closed. The'resultant energizing of the solenoid 21, as above explained, causes the switch 30 to 'be opened to break the circuit 36, which prevents admin on the batteries 35. The catch 33 is now automatically lodged behind the stair 28, causing the dial to be concealed, and remain corrcealed, until another coin is inserted in the meter.

Referring first to the embodiment of my magnetic switch unit shown in Figs. 2 and 3, the said unit is preferably housed in a cylindrical. container 50 having a bottom wall formed integral with the side wall and is sealed by a lid "5! which is bonded to the top of the side wall after the unit is assembled. The container 50 may be formed 'of plastic or other suitable material not susceptible to magnetic attraction. Suspended from the lid 5| are two spaced identical poles 52 formed of copper or other electrically conductive material. Such poles are necked down at the upper end so to form abutment shoulders 54, and have the necks threaded. The lid 5! has tapped openings for threadably receiving the neck portions and when received the necks protrude slightly above the lid and are fitted with nuts 4 T 55 and 55. When the unit is installed for use, conventional wire leads are secured between these nuts. 1

Suspended from the lid by a flat headed screw 63, to lie within the housing is a U-shaped yoke 5'] having its two arms 58 and 59 disposed horizontally in vertical spaced relation, and a post Bl of brass or other suitable non-magnetic material is mounted between the yoke arms for pivotal action about its longitudinal center as an axis. The mounting is effected in any manner calculated to minimize friction. A permanent bar magnet 63 traverses the post Bl with its two ends projecting equidistantly from opposite sides of the post, and also traversng the post is alength of fairly heavy-gauge copper wire 64 lying in a vertical plane forming an acute angle with the vertical plane occupied by the magnet 63, the wire, as can be best seen in Fig. 3, being of a length approximating the distance between the longitudinal axes of the poles 53. Secured to the ends of the wire as by solder, and extending in opposite directions are respective light-gauge conductive wire fingers 65 each bent to coincide with thecurvature of a circle of which the spanning wire is a diameter. The length of the wire fingers is in each instance sufiicient to project the free end thereof beyond the relatedend of themagnet.

The poles 52 are each provided With acylindrical pocket 61 whose axis coincides with the circle on which the wire fingers lie. These pockets 61 are filled with mercurypadhering by surface tension to the walls thereof, and will be hereinafter termed mercury pots. The mercury pots 51 are of sufiicient length and are'so positioned that the extreme ends of the wire fingers will be caused to embedthemselves within the mercury when the magnet 63 is swung-clockwise from the Fig. 3 position to one in which the magnet abuts the poles 52. Whenthemagnet engages the poles 52 the wires lid-and are, however, freely suspended within the mercury, and which is to say that they are notin contact with the floor wall of the respective .pot, wherefor liability of the fine wires-being bentis thus precluded.

In the Fig. 4 embodiment of-my invention two plates 10, one of which is notshown, are screwed or otherwise secured to the .floor and .lid,-re'- spectively, of the container 50. A post-ll is .pivotally mounted between the plates HI, and abar magnet '13 traverses the post. Lengths of spring copper wire I2 made generally to an L shape, are anchored by one leg of each to the bottom plate to have the other leg I4 project horizontallyirom diametrically opposite sides in a plane common to that occupied by the'bar magnet. On the free ends and extending approximately at right angles to the parent branch 14 are terminal fingers 15, z these fingers being oppositely directed. As with the embodiment above described, the fingers .lie

' "Another embodiment of my invention is shown that the magnet becomes part of the said circuit.

In Figs. 6 and '7 another species of my invention is disclosed wherein the magnet 83 is suspended for rotation in the same manner as shown in Fig. 2. The two poles, here designated by 82, are spaced apart at equal distances from and out of alignment with the center of the magnet 83 and are equipped with mercury pots 8! lying in alignment in a plane slightly above the magnet 83 and with their mouths opposingly placed.

Suspended from the lid and lying between the poles 82 are two spaced hanger wires 84 having eyes at their lower ends in alignment with the mercury pots. A copper wire 8! with straight end portions 86 and 88 and with a center yoke section 89 has its said end portions slidably re-- ceived in the eyes 85 with the yoke 89 straddling the magnet 83. The end portion 86 is longer than the portion 88 and extends a substantial distance within its mercury pot when the magnet 83 lies directly between the poles 82 as shown in Figs. 6 and 7, the other end 88, in this said position of the magnet, being slightly withdrawn from the other mercury pot. seen that when the magnet 83 swings clockwise it will engage the yoke 89 and urge the end portion 88 into its mercury pot. The other end portion 86 will, of course, be partially withdrawn from its mercury pot, but there is provided a 1 small horizontal pin 99 protruding from the post 92 arranged to engage an upstanding stop St on the lower arm of the yoke to limit the clockwise rotation of the magnet 83 and hold the same within travel limits insufficient to fully withdraw the end portion 86 from its mercury pot. Therefore, it can be seen that a clockwise swing of the magnet 83 as shown in Figs. 6 and 7 will complete a circuit between the poles via the wire 8! and a minor degree of return travel will sufilce to break this circuit.

In another and unusually compact embodiment of my invention shown in Figs. 8 and 9 two permanent bar magnets 94 are embedded in a horizontally disposed plastic cylinder 95. A vertical post 96 is passed centrally through the cylinder 95 between the magnets 94 and is pivotally mounted between the arms of a yoke 93 in a manner like or similar to that explained. Two short poles I00 are suspended from the lid HM and have mercury pots I92 therein. A copper wire 91 has a displaced upright portion 83 embedded in the cylinder 95 adjacent the rod 96 from which two horizontal portions Ifit and 94 extend, the ends of which intercept and support arcuate wires 98 and 99 arranged for insertion into the mercury pots I92 when the magnets are rotated clockwise, such rotation being limited by the engagement of the cylinder 95 with the poles, and in this regard it will be seen in Fig. 8 that the tips of the wires 98 and 99 extend slightly beyond the cylinder 95 to permit such insertion thereof.

It will be noted that in my control circuit 36 the magnetic switches 31 and 38 should be closed when not attracted by a parked automobile. Therefore the poles of my switch are normally placed in a north-south direction wherein the bar magnet will take a position abutting the poles and closing the switch. Hence on an east-west street it is necessary to provide a compensator Thus it can be such as I ID in Fig. 7, preferably aligned with the. vertical axis of the container 50. A simple form plug I I I to a location wherein the normal position of the primary bar magnet will be such as to close the switch. Preferably the container 59 is filled with kerosene or some other liquid of similar viscosity which will prevent oxidation of the switch parts and will properly dampen the movement of'the bar magnet. Some space must be left in the container to allow for expansion of the liquid.

It has been determined that the rear end of automobiles has a negative polarity. By far the majority of cars have front ends with a positive polarity but there are a considerable number of cars which are found to have a negative polarity at both front and rear ends. Hence when the axis of the parking zone is parallel to the curb as in Figure l, a magnetic switch 31 placed adjacent the rear end of said parking zone and which is arranged to open when its north pole is repelled will always be open when a car is parked. In Fig. 1, I have also shown a second magnetic switch 38 placed near the front end of the park ing zone and adapted to be opened by attraction of its north pole. Such switch 38 will therefore also be open a majority of the times that the parking zone is occupied. I recognize that a prankster might attempt to nullify the parking meter of an occupied parking zone by using a magnet to counter the cars attraction. By the use of two magnetic switches it will be seen that, excepting for the rare cases in which both ends of a parked car evidence a like polarity, it becomes impcssible for a single magnet to close the two widely spaced magnetic switches at one and the same time. Also an article such as a tool box accidently placed near one of the switches could not close both of them.

In Fig. 10 I have illustrated an arrangement of two magnetic switches I37 and I39 for use in so-called parallel parking instances wherein the longitudinal median line of the parking zone is at an angle to the curb. As mentioned above, the polarity of the front end. of a car might be either negative or positive wherefor two oppositely acting magnetic switches are required to assure that at least one of these switches will open irrespective of the cars front-end polarity. 0f the two switches which I show, one is adapted to be opened by attraction of the north pole and the other by repulsion thereof. The two close-coupied. switches could, if desired, be substituted for the single switch 3? at the rear end of the type of parking zone illustrated in Fig. 1, thus assuring, under any condition of changing rear-end polarity, an opening of the circuit when a car is parked in such zone.

In Figs. 1 and 10 I have shown my magnetic switches embedded in the curb but such is not intended as a limitation because the switches would Operate equally as well if placed in the street proper.

The advantages of the invention will, it is thought, have been clearly understood from the foregoing detailed description of the embodiments which I have elected to illustrate. Minor changes in the details of construction will suggest themselves and may be resorted to without departing from the spirit of the invention, whereior it is my intention. that no limitations 'be implied and that the hereto annexed claimsbe givena scope fully commensurate with the broad- :est interpretation to which the employed lan- 'guage admits.

' What I claim is: 1. A magnetic switch unit comprising a closed liquid-tight housing having a nonconductive top 1p1ate, a magnet assembly suspended from the top plate and including a bar magnet mounted for pivotal movement about a vertical axis, a pair of spaced vertical conductive posts passing through and suspended from said top plate and each providing'a binding terminal outside of the housing and a mercury pot inside of the housing, "means within the housing and operatively associated with the magnet for completing a conducjtive connection between the said mercury pots during a selected range of the pivotal travel of the magnet, and a nonconductive liquid filling the 'housing above the magnet for dampening the movement of the latter.

2. A magnetic switch unit comprising a closed liquid-tight housing, a bar magnet pivotally .mounted in said housing for pivotal movement about an axis perpendicular to the longitudinal axis of the magnet, a nonconductive liquid filling the'housing above the magnet for dampenin the movement of the latter, a pair of spaced conductiveposts passing through an outer wall of the housing and each providing a binding terminal outside of the housing and a mercury pot inside the housing, and means operatively associated with the magnet for completing a conductive connection between the said mercury pots during a selected range of the pivotal travel of the magnet.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 685,430 Pearson Oct. 29, 1901 980,155 Hertzberg Dec. 27, 1910 1,289,637 Bruce, Jr Dec. 31, 1918 1,975,762 Behmer Oct, 9, 1934 1,992,214 Katz Feb. 26, 1935 2,068,1 1 Babson Jan. 19, 1937 2,121,179 Sweetland June 21, 1938 2,240,891 Marchant May 6, 1941 2,255,187 Reasoner Sept. 9, 1941 2,323,910 Hubbel July 1 ,1943 2,489,113 Veenstra Nov. 22, 1949 2,520,525 Brouse Aug. 29, 1950 FOREIGN PATENTS Number Country Date 119,086 Great Britain Sept. 19, 1918 170,117 Great Britain Oct, 17, 1921 

